The invention relates to refining systems and methods. In particular, the invention relates to consumable electrode feed systems and methods for refining systems.
Some conventional refining systems utilize ingots as a source of raw metal to be refined. For example, electroslag refining systems may use a consumable electrode, both as a source of raw metal and as a part of an electrical circuit used in the electroslag refining for melting the ingot. These electroslag refining systems and methods, substantial preparation may be needed for placement and utilization of the consumable electrodes. Typically, consumable electrodes have been attached to a vertical motion control apparatus, such as a stub attached to a motive device, which provides mechanical movement of the consumable electrode into the electroslag refining system. The vertical motion control apparatus can comprise a weld between the consumable electrode and a stub of the vertical motion control apparatus, a screw or bolt-like connection between the consumable electrode and a stub of the vertical motion control apparatus, clamps between the consumable electrode and a stub of the vertical motion control apparatus, and other vertical motion control structures between the consumable electrode and a stub of the vertical motion control apparatus. The vertical motion control apparatus also provides electrical contact between the consumable electrode and an electrical power supply.
Electroslag refining melting of the consumable electrode and the movement of the consumable electrode is typically stopped prior to reaching an end of the consumable electrode that is remote from the consumable electrode end in cooperation with the electroslag refining system. The movement stoppage is needed to replace the existing consumable electrode by providing a new consumable electrode for refining in the electroslag refining system, and connecting the new consumable electrode to the vertical motion control apparatus. The movement stoppage is needed to avoid damaging components of the vertical motion control apparatus, for example if vertical motion control apparatus components get too close to the melt in the electroslag refining system. The movement stoppage should avoid contaminating the electroslag-refined melt, for example by contaminants originating from the vertical motion control apparatus. This movement stoppage, while needed in conventional electroslag refining systems, is undesirable since it reduces time that the electroslag refining system is in operation, results in a electroslag refining yield losses, increases electroslag refining system down time, and could increase contamination to the electroslag refining system.
Electroslag refining (ESR) systems and methods are known in the art. For example, electroslag refining systems, methods, and related features are set forth in U.S. Pat. No. 5,160,532 to Benz et al., which also discloses a cold induction guide (CIG) transfer device. Additional electroslag refining systems, methods, and related features are set forth in the following U.S. Patents, all of which are assigned to the Assignee of the instant invention and of which the contents are fully incorporated by reference: U.S. Pat. No. 5,160,532 to Benz et al.; U.S. Pat. No. 5,310,165 to Benz et al.; U.S. Pat. No. 5,325,906 to Benz et al.; U.S. Pat. No. 5,348,566 to Sawyer et al.; U.S. Pat. No. 5,366,206 to Sawyer et al.; U.S. Pat. No. 5,472,177 to Benz et al.; U.S. Pat. No. 5,480,097 to Carter, Jr. et al.; U.S. Pat. No. 5,649,992 to Carter, Jr. et al.; U.S. Pat. No. 5,649,993 to Carter, Jr. et al.; U.S. Pat. No. 5,683,653 to Benz et al.; U.S. Pat. No. 5,769,151 to Carter, Jr. et al.; U.S. Pat. No. 5,809,057 to Benz et al.; and U.S. Pat. No. 5,810,066 to Knudsen et al.
Further, difficulty encountered in forming castings, for example large diameter castings, such as those with diameters greater than about 18 inches (about 45 centimeters) may be increased during movement stoppage, connecting and changing the consumable electrode. The casting process of a large diameter ingot typically uses several consumable electrodes, which have been connected to the vertical motion control apparatus. Inhomogeneous regions may arise in the resulting casting during any consumable electrode connection operations. These inhomogeneous regions may result from minor constituent variations in the consumable electrodes, contaminants that may enter the electroslag refining melt during movement stoppage and consumable electrode connection operations, differing electroslag refining conditions before and after movement stoppage, and other such electroslag refining variables. These inhomogeneous regions are, of course, undesirable in the resulting casting and any article, such as, but not limited to, turbine components formed from the casting.
Thus, a need exists for providing consumable electrodes for electroslag refining systems and methods that avoid movement stoppage of electroslag refining. Further, a need exits for providing electroslag refining systems and methods that avoid yield loss, contamination during electroslag refining, and damage to vertical motion control apparatus. Further, a need exists for electroslag refining systems and methods that avoid forming inhomogeneous regions during consumable electrode movement stoppage and consumable electrode connection operations.
An aspect of the invention sets forth a consumable electrode feed system for a refining system. The consumable electrode feed system comprises a side feed device that feeds consumable electrodes to a refining system in a first direction; a refining feed device that feeds consumable electrodes to a refining system in a second direction, in which the second direction being generally orthogonal to the first direction; and a connection system for connecting fed consumable electrodes to each other. The consumable electrode feed system allows for a predetermined amount of a consumable electrode to be refined in the refining system, and can position another consumable electrode above a previously fed consumable electrode. The connecting system then can connect a fed consumable electrode to a previously fed consumable electrode thus avoiding interrupting refining.
The invention sets forth a method for feeding consumable electrodes to a refining system. The method of feeding comprises feeding consumable electrodes to a refining system in a first direction; feeding consumable electrodes to a refining system in a second direction, the second direction being generally orthogonal to the first direction; connecting fed consumable electrodes to each other; and refining the consumable electrodes as they are fed to the refining system. The method permits a predetermined amount of a consumable electrode to be refined in the refining system, feeding another consumable electrode above a previously fed consumable electrode, and connecting a consumable electrode to a previously fed consumable electrode for avoiding refining operation stoppage.
A further aspect of the invention provides a consumable electrode feed system for providing consumable electrodes to an electroslag refining system. The electroslag refining system comprises a cold induction guide. The consumable electrode feed system comprises a side feed device for feeding consumable electrodes to a refining system in a first direction, in which the side feed device is selected from at least one of conveyors, cranes, tracks, lifts, and combinations thereof for orienting a consumable electrode in a disposition to be fed to the refining feed device; a refining feed device for feeding consumable electrodes to a refining system in a second direction, wherein the second direction is generally orthogonal to the first direction and the refining feed device is selected from caterpillar devices, treaded devices, belt devices, chain devices, and combinations thereof for controlled movement of the consumable electrode to the refining system; and a connection system for connecting fed consumable electrodes to each other. The connection system is selected from at least one of weld connection systems, brazing connection systems, soldering connection systems, fusing connection systems, and combinations thereof. As a predetermined amount of a consumable electrode has been refined in the refining system, another consumable electrode is positioned above a previously consumable electrode by the side feed device. The connecting system then can connect a fed consumable electrode to a previously fed consumable electrode, thus avoiding refining operation stoppage for providing consumable electrodes for refining.
Another aspect of the invention provides an electroslag refining system comprising a consumable electrode feed system. An electroslag refining system comprises an electroslag refining structure; a cold health structure; and a consumable electrode feed system for providing consumable electrodes to the electroslag refining system. The consumable electrode feed system comprises a side feed device that feeds consumable electrodes to the electroslag refining system in a first direction; a refining feed device that feeds consumable electrodes to the electroslag refining system in a second direction, the second direction being generally orthogonal to the first direction; and a connection system that connects fed consumable electrodes to each other. The electroslag refining system with the consumable electrode feed system allows a predetermined amount of a consumable electrode to be refined in the electroslag refining system, and another consumable electrode is positioned above a previously consumable electrode by the side feed device. The connecting system connects a fed consumable electrode to a previously fed consumable electrode, thus avoiding refining operation stoppage for providing consumable electrodes for refining by the electroslag refining system.
These and other aspects, advantages, and features of the invention will become apparent from the following detailed description, which, when taken in conjunction with the annexed drawings, where like parts are designated by like reference characters throughout the drawings, disclose embodiments of the invention.